The use of fixtures for location and guidance of a drill bit to drill holes in a workpiece, such as a piece of wood, for pocket joints is well known. A pocket hole is one that is made at an angle in a piece of wood and a wood screw is inserted into the hole to join the workpiece to another wood piece. The screw is recessed in the hole and is not exposed.
U.S. Pat. No. 4,955,766 discloses the combination of a drill bit with a stop collar and a fixture used for making pocket holes at an angle to a surface of the workpiece. The fixture has an L-shaped base with one leg serving as a guide portion for the workpiece and the other as a portion to hold a clamping device, shown as an over-center clamp. An angled channel having a stop flange at its upper end is provided on the guide portion leg. The drill bit is inserted into the channel and drills a hole at an angle in the workpiece up to the point where the stop collar engages the flange. The fixture of this patent is somewhat complicated in that the over-center clamp is required as well as the drill bit with a stop collar. Also, in this patent the workpiece is held against a flat surface and the wood chips produced during the drilling can only escape up through the channel. This has a tendency to clog the drill bit and to adversely affect its efficiency.
U.S. Pat. 1,128,970 discloses a fixture for drilling holes for dowels, the holes being drilled transverse to the workpiece. The workpiece is held in a base by a clamp and a carriage containing bushings for passage of a drill bit into the workpiece is moveable over the base to place the hole of a over a proper location on the workpiece. While the clamp of this patent is relatively simple as compared to an over-center clamp, the fixture does not show drilling of an angled pocket hole.